Article
Computer Science, Information Systems
Tamiris Grossl Bade, Hassan Hamad, Adrien Lambert, Herve Morel, Dominique Planson
Summary: The instability of threshold voltage in p-GaN gate high electron mobility transistors (HEMTs) has been identified in recent years. This can cause reliability issues in switching applications and may be accompanied by other degradation mechanisms. In this study, a Vth measurement protocol originally established for SiC MOSFETs is applied to GaN HEMTs using the triple sense protocol, which involves preconditioning the transistor gate with voltage bias. Experimental results have confirmed that the proposed protocol enhances the stability of Vth measurement, even after experiencing degrading voltage bias stress on both drain and gate.
Article
Engineering, Electrical & Electronic
Thorsten Oeder, Martin Pfost
Summary: This study investigates the threshold voltage (V-th) instability of p-gate GaN HEMTs induced by gate bias. Different effects are observed for devices with ohmic gate and Schottky gate, causing different variations in V-th. Electron depletion and trapping, as well as hole accumulation and trapping, are identified as the main causes of this instability.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2021)
Article
Engineering, Electrical & Electronic
Zuoheng Jiang, Mengyuan Hua, Xinran Huang, Lingling Li, Chengcai Wang, Junting Chen, Kevin J. Chen
Summary: In this article, the impacts of off-state gate bias on the dynamic on-resistance in p-GaN Gate high-electron-mobility transistors are investigated. It is found that more negative off-state gate bias can worsen the degradation of dynamic on-resistance, especially when switching with a high drain bias. The influences of off-state gate bias on switching transients and off-state stress are explored to reveal the underlying mechanisms.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2022)
Article
Engineering, Electrical & Electronic
Injun Hwang, Jaejoon Oh, Sun-Kyu Hwang, Boram Kim, Jun Hyuk Park, Joonyong Kim, Jongseob Kim
Summary: This study analyzes the threshold voltage drift of p-GaN gate high-electron mobility transistor (HEMT) under high-voltage and hard switching conditions. A method is proposed to accurately measure the dynamic threshold voltage by correcting the charging current of the internal drain capacitance. The experimental results show that the dynamic threshold voltage rapidly increases and saturates during the switching operation, and it has a linear relationship with the gate turn-on voltage.
IEEE ELECTRON DEVICE LETTERS
(2022)
Article
Computer Science, Information Systems
Xiaodong Zhang, Xing Wei, Peipei Zhang, Hui Zhang, Li Zhang, Xuguang Deng, Yaming Fan, Guohao Yu, Zhihua Dong, Houqiang Fu, Yong Cai, Kai Fu, Baoshun Zhang
Summary: This study investigates the variation of threshold voltage in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) with a SiNx/SiON composite gate dielectric on Si substrates. The results show that the MIS-HEMTs with the SiNx/SiON composite gate dielectric exhibit superior threshold voltage uniformity and smaller threshold voltage hysteresis compared to the reference device with only SiNx gate dielectric. The study also confirms that the variation of device threshold voltage is mainly related to trapping process by the interface states.
Article
Engineering, Electrical & Electronic
Chao Feng, Qimeng Jiang, Sen Huang, Xinhua Wang, Xinyu Liu
Summary: In this study, the recovery of transient threshold voltage (V-TH) in Schottky-type p-GaN Gate AlGaN/GaN high-electron-mobility-transistors (HEMTs) was measured using a microsecond-level fast-tracking method. It was found that applying an appropriate positive forward gate bias during the gate turn-off transient can significantly accelerate the recovery speed of V-TH, contradicting the conventional use of negative gate turn-off voltage. The dominant recovery mechanism was speculated to be the electrical-field assisted emission of electron trap in the p-GaN depletion region, which was supported by comparing the recovery process between predamage device and fresh device. An electron trap with a depth of 0.30 +/- 0.03 eV was extracted using the Arrhenius plot. This work is of great importance in understanding the mechanism of threshold voltage recovery and suggests that a positive gate base voltage can accelerate the V-TH recovery.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Engineering, Electrical & Electronic
Han Xu, Jin Wei, Ruiliang Xie, Zheyang Zheng, Jiabei He, Kevin J. Chen
Summary: Research has shown that the threshold voltage (V-TH) of enhancement-mode Schottky-type p-GaN gate HEMTs is dependent on the drain bias, requiring higher gate voltage to switch on the transistor due to the influence of stored charges in the floating p-GaN layer. A proposed SPICE-compatible equivalent circuit model accurately predicts the dynamic V-TH characteristics and switching behaviors of power electronics circuits, showcasing its advantages in power transistor applications.
IEEE TRANSACTIONS ON POWER ELECTRONICS
(2021)
Article
Physics, Applied
Ryota Maeda, Kohei Ueno, Atsushi Kobayashi, Hiroshi Fujioka
Summary: This study reports on AlN barrier Al0.5Ga0.5N high electron mobility transistors (HEMTs) prepared by pulsed sputtering deposition. By selectively regrowing n-type GaN contacts, degenerate properties were achieved with excellent electron concentration and mobility, resulting in a record low contact resistance. The AlN/Al0.5Ga0.5N HEMTs exhibited remarkable DC output characteristics, demonstrating potential applications for high-power and high-frequency AlGaN electron devices.
APPLIED PHYSICS EXPRESS
(2022)
Article
Chemistry, Physical
You-Chen Weng, Ming-Yao Hsiao, Chun-Hsiung Lin, Yu-Pin Lan, Edward-Yi Chang
Summary: A high-pressure GaN nucleation layer was inserted in an AlGaN/GaN HEMT to improve its electrical properties. By optimizing the V/III ratio during the growth of the high-pressure GaN layer, the edge dislocation density in the layer was significantly reduced. Experimental results showed lower off-state leakage current, higher maximum I-D and G(m), and lower on-state resistance, indicating the effectiveness of the high-pressure GaN nucleation layer in enhancing the performance of the AlGaN/GaN HEMT.
Article
Engineering, Electrical & Electronic
Sheng Zhang, Ke Wei, Yichuan Zhang, Xiaojuan Chen, Sen Huang, Guoguo Liu, Yingkui Zheng, Tingting Yuan, Xinhua Wang, Yankui Li, Jiebin Niu, Xinyu Liu
Summary: PEALD SiN gate dielectric is used in AIGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MIS-HEMT), resulting in devices with small threshold voltage hysteresis, decreased leakage current, and good threshold voltage stability. The increased mobility of 2-DEG and suppressed current collapse lead to high power density and power-added efficiency in continuous-wave mode at 30 GHz.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Chemistry, Multidisciplinary
Kuan-Chang Chang, Xibei Feng, Huangbai Liu, Kai Liu, Xinnan Lin, Lei Li
Summary: This study proposes an effective and accurate computational-fitting method for extracting the mobility of GaN HEMT. The method involves measuring the total resistance between source and drain at different gate voltages and fitting the total resistance with respect to the overdrive voltage to determine the carrier mobility and the non-gate resistance.
Article
Engineering, Electrical & Electronic
Arathy Varghese, Chinnamuthan Periasamy, Lava Bhargava, Surani Bin Dolmanan, Sudhiranjan Tripathy
Summary: The research involves the development of a C-MOSHEMT sensor for pH detection application, with modeling, fabrication, and sensitivity analysis conducted. Experimental results show the impact of increasing sensing area on sensitivity.
IEEE SENSORS JOURNAL
(2021)
Article
Engineering, Electrical & Electronic
M. Wzorek, M. Ekielski, E. Brzozowski, A. Taube
Summary: In this study, gold-free Cu/Pd2Si Schottky contacts to AlGaN/GaN-on-Si HEMT heterostructures were analyzed. The effects of post-gate annealing on the electrical properties of the contacts were examined. The micro-structures of the diodes were analyzed using transmission electron microscopy (TEM) and the electrical properties were determined via temperature-dependent current-voltage (I-V-T) measurements.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Article
Engineering, Electrical & Electronic
Jialin Li, Yian Yin, Fengbo Liao, Mengxiao Lian, Xichen Zhang, Keming Zhang, Yafang Xie, You Wu, Bingzhi Zou, Zhixiang Zhang, Jingbo Li
Summary: This article proposes the use of a stepped channel to increase the threshold voltage(Vth) for the first time. Its working mechanism is explained and the step height is optimized. By introducing a composite stepped gate and p-GaN buried layer with field plate, the threshold voltage can be as high as 3.5V and the breakdown voltage can reach 2440V with a high figure of merit (FOM) of 2.57GW/cm2. The composite stepped gate GaN-based HEMT shows great potential in high-power devices and has advantages in communication system applications.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2023)
Review
Materials Science, Multidisciplinary
Yang Jiang, Wenmao Li, Fangzhou Du, Robert Sokolovskij, Yi Zhang, Shuhui Shi, Weiguo Huang, Qing Wang, Hongyu Yu, Zhongrui Wang
Summary: This paper provides a comprehensive review of recent advancements in gallium nitride (GaN)-based gas sensors, with a focus on their dynamic response-related behaviors. The representative device structures of GaN-based gas sensors and their figures of merits are overviewed. The various techniques employed in the fabrication of these sensors are examined. The dipole-based sensing mechanism, the thermodynamic model governing gas absorption and desorption processes, and the relationship between response and recovery times with temperature and concentration are explored.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Applied
Seungyoon Kang, Jongseob Kim, Joo-Hyoung Park, Chi Kyu Ahn, Chang-Houn Rhee, Min Su Han
Article
Chemistry, Physical
Jongseob Kim, Seung-Cheol Lee, Sung-Hoon Lee, Ki-Ha Hong
JOURNAL OF PHYSICAL CHEMISTRY C
(2015)
Article
Chemistry, Multidisciplinary
Hoon Ryu, Jongseob Kim, Ki-Ha Hong
Article
Chemistry, Physical
Jongseob Kim, Ki-Ha Hong
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2015)
Article
Chemistry, Physical
Ki-Ha Hong, Jongseob Kim, Lamjed Debbichi, Hyungjun Kim, Sang Hyuk Im
JOURNAL OF PHYSICAL CHEMISTRY C
(2017)
Article
Chemistry, Physical
Jongseob Kim, Choong-Heui Chung, Ki-Ha Hong
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2016)
Article
Chemistry, Physical
Jongseob Kim, Sung-Hoon Lee, Choong-Heui Chung, Ki-Ha Hong
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2016)
Article
Nanoscience & Nanotechnology
Jongseob Kim, Hyungjun Kim, Mahesh Chandran, Seung-Cheol Lee, Sang Hyuk Im, Ki-Ha Hong
Article
Chemistry, Physical
Jongseob Kim, Kyung Yeon Kim, Hyoung Joon Choi, Ki-Ha Hong
JOURNAL OF PHYSICAL CHEMISTRY C
(2014)
Article
Chemistry, Physical
Jin Hyuck Heo, Jongseob Kim, Hyungjun Kim, Sang Hwa Moon, Sang Hyuk Im, Ki-Ha Hong
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2018)
Article
Chemistry, Physical
Jongseob Kim, Sung-Hoon Lee, Sang Hyuk Im, Ki-Ha Hong
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2020)
Article
Engineering, Electrical & Electronic
Injun Hwang, Soogine Chong, Younghwan Park, Sun-Kyu Hwang, Boram Kim, Joonyong Kim, Jaejoon Oh, Jun Hyuk Park, Dong-Chul Shin, Min Chul Yu, Jai Kwang Shin, Jongseob Kim
Summary: This study focuses on the transient measurement of the drift region potential in AlGaN/GaN HEMT under high power state, revealing that the propagation speed of high electric field in the device is influenced by the drift region voltage, and proposing that trapping of hot channel electrons is causing this effect.
IEEE ELECTRON DEVICE LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Jaeho Kim, Jaejoon Oh, Jongseob Kim, Jaehee Cho
Summary: By depositing various dielectrics on the surfaces of AlGaN/GaN-based HEMT devices, it was observed that the 2DEG sheet carrier density increased by 30%, leading to improved device performance in terms of output and transfer characteristics. Additionally, the deposition of dielectrics helped suppress current collapse in the HEMT devices.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2021)
Article
Engineering, Electrical & Electronic
Injun Hwang, Soogine Chong, Dong-Chul Shin, Sun-Kyu Hwang, Younghwan Park, Boram Kim, Joonyong Kim, Jaejoon Oh, Jun Hyuk Park, Min Chul Yu, Woochul Jeon, Jai Kwang Shin, Jongseob Kim
Summary: The research suggests using wafer level transient voltage measurement (WLTVM) to estimate the short circuit capability of AlGaN/GaNHEMT devices. The study found that short circuit failure is mainly attributed to degradation in the drift region. By measuring transient potential changes, it is possible to predict short circuit failures and take timely action.
IEEE ELECTRON DEVICE LETTERS
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Hoon Ryu, Jongseob Kim, Ki-Ha Hong
2014 INTERNATIONAL CONFERENCE ON SIMULATION OF SEMICONDUCTOR PROCESSES AND DEVICES (SISPAD)
(2014)